When I change from an 8" Concrete Block wall to a 10" Concrete Block wall, my drawing gets bigger by 2",
why?

A wall that does not have a material which differentiates inside from outside is considered a symmetrical wall.
When a symmetrical wall is converted to a different wall type, SoftPlan references the center of the existing wall
to the center of the new wall and the difference in thickness is split equally between both sides of the wall. To
allow the walls to line up either the surface or the bearing edge, add a surface to the symmetrical wall that is 0"
in thickness, and de-select the SoftList option in the wall definition for the new material.If the wall already
exists on the plan, then simply Edit the wall and ensure that the Display Exterior side is in the correct
direction. Then the walls can be accurately changed when changed to another type. Align the walls exterior sides.
If the wall is newly drawn, it will require a 3rd click to set the Exterior side of the wall as it is no longer
symmetrical.